Heat recovery steam generators (HRSG) are one of four major components typically associated with power generation. The other major components are the gas turbine, the steam turbine, and the generator(s). The HRSG recaptures the excess heat energy that is produced in the turbine's combustion process, and such energy can be utilized in a steam turbine to generate additional usable energy.
Power generation system owners often need to manage the startup and shutdown cycles of the gas turbine system based on a number of factors including energy demand, fuel prices, energy prices, predicted load, power system conditions, emissions, etc. Therefore, the gas turbine components must withstand numerous heating and cooling cycles. This cycling tends to create mechanical wear and fatigue in the various parts due to thermal expansion and contraction.
One of the challenges facing gas turbine operators involves balancing the power output to service demand cycles and transients without creating unnecessary wear or damage to the multitude of parts that make up the HRSG.